Google says it will hit its 100% renewable energy target in 2017

Google has made a major commitment to green energy, pledging to buy 100% of its energy requirements from renewable sources in 2017.

The company is already "the world's largest corporate buyer of renewable power," SVP of technical infrastructure Urs Hölzle wrote in a blog post announcing the news, and it now plans to "[directly buy] enough wind and solar electricity annually to account for every unit of electricity our operations consume, globally."

This includes both Google's offices and its much more power-hungry data centres.

It's important to note: This isn't the same as having all of Google's operations directly powered by renewable energy. Because of the way power grids work, that's not necessarily possible - the only source of power for a data centre might be a nearby coal power station, for example.

"The reality of today's electricity grid means that we are unable to power our operations directly from wind and solar farms during every hour of the day," Google said in a white paper about its green ambitions. But it means that Google will be buying enough energy from renewable sources to account to the entirety of its operations.

As data centres continue to grow around the world, they suck up extraordinary amounts of energy. They use 3% of the world's electricity supply - a figure that is estimate to triple over the next decade. Tech companies are increasingly pledging to draw much - or all - of their energy from renewable sources, but none are on the same scale, so soon, as Google's commitment on Tuesday.

"The science tells us that tackling climate change is an urgent global priority," Hölzle wrote. "We believe the private sector, in partnership with policy leaders, must take bold steps and that we can do so in a way that leads to growth and opportunity. And we have a responsibility to do so - to our users and the environment."